An all para-oriented polybenzimidazole is a desirable product because it has the potential of possessing outstanding physical properties. In the preparation of such polymers, the conventional practice is to condense two monomers, e.g., a tetraamine and a tetraacid. However, the polymers prepared by the prior art methods are not entirely satisfactory because of their low molecular weight.
It is an object of this invention, therefore, to provide AB-monomers which can be used in preparing a high molecular weight, all para-oriented polybenzimidazole.
Another object of the invention is to provide an intermediate for use in preparing the AB-monomers.
A further object of the invention is to provide a process for synthesizing substituted phenyl-benzimidazo compounds.
Still another object of the invention is to provide a process for preparing poly[(2,6-imidazobenzimidazo)1,4-phenylene].
Other objects and advantages of the invention will become apparent to those skilled in the art upon consideration of the accompanying disclosure.